Cytokinesis in the nematode C elegans is thought to be regulated by several compounds including calcium. We wish to elucidate the role of one calcium related compound, calmodulin in cytokinesis and determine if it plays a role in regulation. Its is suspected that calmodulin may play a crucial role in the first stage of cytokinesis, the setting down of the cleavage furrow. A caged calmodulin inhibitor will be injected into early C elegans worm oocytes. Conventional light microscopy will be used initially for these experiments to track and uncage the calmodulin inhibitor. By using UV light the calmodulin inhibitor will be uncaged in embryos prior to their entry into cytokinesis. The effect of inhibiting calmodulin, on cytokinesis will be observed. The uncaged calmodulin inhibitor should bind free calmodulin prior to their entry into cytokinesis. So it should be possible to determine whether cytokinesis can occur in the absence of calmodulin. As a follow up to the initial study with light microscopy, multiphoton microscopy will be used to uncage the calmodulin for better localization in the embryo.